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Coming hot on the heels of our recent test of the M5, our brief time with the 2006 BMW M6 was especially enjoyable as we had already learned enough of the Sequential Manual Gearbox's behavior to really tap into the M6's performance. The same basic drivetrain powers both cars: an operatic 500-horsepower 5-liter V10 engine coupled to the seven-speed SMG. Performance in both cars is startling but kept doable with stability control, adjustable damping, and numerous engine and transmissions modes. The M5 actually has the better drag coefficient of the two, but the M6 evens out any performance edge with a slight weight advantage.
The M6 looks distinctly more purposeful than a regular 6 series. As with most current BMWs, styling is a controversial issue, and the rear end of the M6 makes an easy target: in our time with the car we heard it compared with a bathtub and a tramp's hat. This 6-series doesn't live up to the previous generation's design, but the no-nonsense treatment given to the 2006 M6 is an improvement to our eyes. The standard 19-inch wheels are an especially bold upgrade, with a thin five-spoke design showing off the brake hardware.
BMW provides a comprehensive roster of technophile goodies, most of which we've seen in other BMWs: iDrive is the now-familiar--if unloved--main cabin control interface; Bluetooth integration is offered along with voice control of other interior systems; and the same split-screen navigation setup we've always liked is standard.
Major options include the heads-up display ($1,000) that we saw in the M5, Sepang Merino leather ($3,500), comfort access ($1,000), high-definition radio ($500), and carbon-fiber interior trim ($300). With a stiff gas guzzler penalty of $3,000 and the $695 destination charge, our M6 stickered for a whopping total of $106,690. The 2006 BMW M6 is performance-oriented, but passengers are treated well as they fly along--as well they should be in a coupe in this price range. As in the 2006 BMW M5, the full leather option in our M6 impressed us with the material and the degree of coverage. Our M6's carbon-fiber interior trim, however, left us rather cold. The dark mesh of the trim lacked the warmth of the wood trim we'd seen in the M5, especially against the light-hued seats, dash, and console. The carbon fiber does make a nice reminder of the lightweight roof panel overhead, but most buyers will probably forgo the interior trim.
The BMW M6's optional carbon-fiber interior left us cold.
The M6 we tested also lacked the $1,900 multifunction seat option, making do with the standard heated front seats and their 16-way power adjustments, including lumbar and thigh support. The seat-cooling option was not present in our M6, which we missed, but we were just fine without the gee-whiz active bolstering of the seats in the M5. Support was very good and with the power tilt and telescoping steering wheel, getting comfortable was easy. The main gauges are large and clear, with a digital information display between them. The optional heads-up display shows a virtual tachometer, current gear and speed, and warning messages where the driver can see them while maintaining a view of the road ahead.
We noted in the M5 how difficult it is for the driver to reach the six-CD magazine located in the glove box, which augments the single-disc slot in the dash. In the M6, a slightly wider center console makes it all but impossible. And we felt slightly claustrophobic in the M6, which is almost four inches shorter than the M5. Headroom was adequate yet we still felt cramped, possibly due to having been in the M5 immediately before.
A large center console makes for a snug ride but poses a significant obstacle to loading CDs in the glove box-mounted magazine.
In terms of layout and space, the interior reminded us of the Porsche 928, a car which also seemed to fit tighter than the overall size would suggest. As in the 928, the M6's rear seats are for small children only. A ski pass-through from the spacious trunk is standard.
Interior electronic systems all performed as we've come to expect. The navigation system plots routes and zooms speedily--zooming being one rare setting for which the iDrive dial is the perfect controller. Voice control for the audio, navigation, and Bluetooth systems was effective. The same top-notch audio system we saw in the M5 is again standard, and Sirius satellite radio is a $595 option. The M6 is also equipped with high-definition radio for an additional $500.
Bluetooth hands-free calling comes as standard on the M6, and we had no problem hooking up our phone to make calls.
The comfort access option allows entry and engine-starting with the key pocketed. Numerous other lighting and central locking options are controllable with iDrive, as is the automatic air recirculation system. Climate control requires some iDrive use for setting airflow, but there are dedicated controls for fan speed and temperature for both front seating positions. The 2006 BMW M6 features one of the most potent production-car engines currently available. Thanks to individual throttle bodies for each of the 10 cylinders, an oversquare bore-to-stroke ratio and steplessly variable valve-timing, the 5-liter unit revs with amazing ease. Power is always available, and mashing the throttle to hear the ensuing bark and crescendo from the four big exhaust outlets becomes addictive. As we noted in our M5 review, the production of 100 horsepower-per-liter of displacement without forced induction is impressive in 2-liter engines such as the VTEC four-cylinder engines found in Honda and Acura models; the same relative output, along with an 8,000rpm redline in a 5-liter V10 is almost magical.
The M6 shares its monstrous 500-horsepower V-10 engine with the 2006 BMW M5.
Acceleration is rated by BMW at 4.5 seconds from 0 to 60mph, the same as for the M5. The M6 is about 100 pounds lighter than the M5, thanks mainly to the carbon-fiber roof panel, a first for a production car, and this--along with the resultant lower center of gravity--makes the M6 feel slightly more responsive.
The main obstacle facing an eager M5 or M6 driver is the unorthodox SMG transmission. Novices must endure lots of hesitant starts and head-bobbing low-speed shifts, but with practice things can be smoothed out for creeping around town. SMG really shines when the most is being asked of it, and of course pushing the M6 this hard on public roads draws attention. Our test car's Interlagos Blue Metallic paint turned heads everywhere we went, and this color is potentially license-threatening when driving the M6 at anywhere approaching its potential.
Among the buttons on the M6's thick M-stitched steering wheel is the M-Drive toggle, which instantly configures the electronic damping control, transmission and engine modes, dynamic stability control, and heads-up display to the driver's preset settings. The purest modes for the engine (P500 Sport, giving 500 horsepower and the crispest throttle response) and transmission (Sport 6 for ultrafast upshifts) are available only with M-Drive activated. Stability control can be completely defeated for sideways shenanigans, but is probably best left in M mode, where some wheel spin is allowed. Speed-sensitive variable-assist steering with a special M-Dynamic mode provides excellent feel and feedback over all road conditions.
The steering wheel-mounted M button activates the M6's optimum performance settings.
Despite our gradual embrace of SMG in the M5 and then the M6, we are relieved to hear that BMW plans to offer a standard six-speed manual with the 2007 M5. Under full throttle, SMG shifts faster and cleaner than most people can match and blips the throttle automatically for perfectly rev-matched downshifts every time. But its foibles can be frustrating under normal conditions, and many buyers will opt for the direct feel and familiarity of the six-speed. Hopefully, the M6 will also get the choice--perhaps when the recently announced convertible debuts for the 2008 model year.
While EPA fuel economy ratings are the same for both the M5 and M6 at 12mpg in the city and 18mpg highway, the M6's slightly better combined rating saves it $700 in gas-guzzler tax over the M5. The 2006 BMW M6 has yet to be crash-test rated by the NHTSA, but safety features abound. Park Distance Control is standard, and while no rear view camera option is available, it is effective enough with its overhead view of the car, color-coded intrusion zones, and progressive proximity audio warnings. Adaptive headlights are also standard on the xenon beams, as is dynamic automatic leveling.
BMW's radar-based Park Distance Control gives a color-coded overhead pictogram of any obstacles close to the car's bumpers.
Tire-pressure monitoring is standard, as expected with this level of performance. The rain-sensing wipers weren't called for during our week with the car, but the system worked very well in the 550i we tested previously.
Dual-stage, dual-threshold "smart" airbags protect both front occupants, with door-mounted side-impact bags also standard. A head protection system covers both front and rear passengers, and interlocking door anchors improve crashworthiness in side impacts. Serious collisions trigger the disconnection of alternator, fuel pump, and starter from the battery and also unlock the doors and turn on the hazard and interior lights.
BMW's standard new-vehicle warranty is good for 4 years or 50,000 miles, with all scheduled maintenance included. Roadside assistance is also provided during this period. Rust-through protection covers the body for a period of 12 years.